This application seeks to develop a "multi-metal chip" that will facilitate rapid and accurate point- of-care measurement of blood metal concentration, including manganese (Mn), zinc (Zn), cadmium (Cd), and lead (Pb) in children. Whole blood analysis is the most common method for determining metal exposure and assessment of health outcomes, yet sample collection from children poses multiple challenges, including parent consent and child assent, and the ability to give blood (especially in studies that require repeated measurements). This application aims to transform the current paradigm by demonstrating a "laboratory-in-a-chip" sensor capable of rapid analysis (5-10min) on small blood samples (2 drops from a single lancet puncture). We propose to develop this system for highly sensitive measurement of Mn, Zn, Cd, and Pb in whole blood by accomplishing the following specific aims: 1) develop a lab-on-a-chip sensor for a rapid, point-of-care multi-metal analysis in whole blood, and 2) conduct a field test and determine the applicability of the multi-metal sensor for measuring blood metal concentration in children residing near a ferromanganese refinery. Our approach will be to integrate anodic stripping voltammetry with our deep expertise in lab-on-a-chip and microfluidics. Our multidisciplinary team of engineers, chemists, and environmental health has taken the first steps towards developing such a device. We have demonstrated feasibility of the sensor through pilot tests, and are now poised to fully develop the sensor system for point-of-care application. The uniqueness of this study is the child-friendly requirement of only drops of blood for analysis, low- cost (disposable), ability to conduct multiple blood measurements, and its potential use in large- scale clinic, occupational and research settings, such as the National Children's Study and the National Health and Nutrition Examination Survey. PUBLIC HEALTH RELEVANCE: This application seeks to develop a "laboratory-in-a-chip" sensor for rapid and accurate point-of- care measurement of metals (manganese, zinc, cadmium, and lead) blood. Whole blood analysis is the most common method for determining metal exposure and assessment of health outcomes, yet sample collection from children is highly problematic. The uniqueness of this study is the child-friendly requirement of only drops of blood for analysis, low-cost, ability to conduct multiple blood measurements, and potential use in large-scale clinic, occupational and research settings.